Pipe or tube bending machine



March 17, 1925.

1720011157 I Jbim Elfawe:

Patented Mar. 17, 1925.

- UNITED *s rarus rarelarv OFFICE.

JOHN. HENRY nAwiis, or LONDON, ENGLAND.

PIPE on TUBE BENnmG riacnnvr...

Application filed March 7, 1923. .Serial in. 623,470.

' To all whom it may ozmcerm Be it known that I, JOHN HENRY Hnwn's,

a subject of the King of Great Britain, of 14 to 19 Tottenham Mews, Tottenham Street, London, England, have invented ';a new and useful Improvement in or'R-elating to Pipe or Tube'Bending Machines, of which the following isia specification.

This invention relates to tube or pipe bending machines of the kind wherein the tube to be bent is placed between the curved periphery of a former or radius wheel and a straight shield, and a roller carried by a radial lever is adapted to travel over the back of the shield to transmit the bending force therethrough to the tube and bend the same around the said formerwor radius Wheel.

' In apparatus of this kind the bending roller has always been carried upon a radial lever so as to engage the shield on a radial line passing through the bending and former could not move towards one. an-

other when the edges were once in engagement and consequently the dlStIllPHtlOIi of the pressure on the pipe was not satisfactory.

- It has also been proposed to employ-with an inner former or radius wheel of slightly less depth than the tube an outer shield or former also ofslightly less depth than the tube and divided longitudinally into two halves secured together by strapsand in this arrangement the curved faces of the two halves which bear upon the tube were made.

in two different curves, a longitudinal gap being left alongside the tube where the curves meet, the arrangement being such that the pressure exerted tended to open I out the divided former or shield and thus distribute the pressure.

It is the object of. the present-invention to provide an improved apparatus by which very thin tubes may be bent withoutv distortion and without being filled, the improved machine, being,l10wever, also useful for bending tubes of thick gauge when required.

this end and according to the ,firstand princ pal feature of the present invention the bending roller is somounted on its lever as to always engagethe shield and transmitthe bending force therethrough tothetube at a p'oint between 10 a1'1d25", but preferably approximately 159beyond a radial line passing through the bending point.

I Secondly, the lever carrying the bending roller is preferably cranked or offset forwardly so that when the parts are assembled for operation with the lever lying at substantially with the tube to be bent, the

roller will be so'placed as to engage the shield'at thebeforementioned correct angular position as soon as the handle'ispulled forward toexert thebending pressure.

in Thirdly, the former or radius wheel is flanged, outward sufliciently beyond its curved ,'face to permit the curved face" of -the solid shieldwhich is made with thin or knife like edges to slide to and from the tube-between the said flanges which act as a guide, and thus form an effective support for holding the tube and properly distributing the pressure thereon without the View of so T theoperation being obstructed during working, as isthe case where a cover'plate and interchangeable form wheel are employed, and thus the'operation of bending tubes to Fourthly, each "machine is preferably provided with adjustable and interchangeable forms or radiusv wheels and bearing studs and means for adjusting the posi- "tionofthe roller to adjust the machine for dealing' with tubesovera given range of sizes and also to enablepartially bent tubes to be accommodated in the machinewhen Sbends and so forth are being'made.

' The a'ccompanying drawings show one construction of the improved pipe bending machine.

.Figure 1 is a plan,

' Fig. 2 is a'front elevation of Fig. 1, and Fig. 3 is a side elevation of Fig. l from the left.

g Land 5are details. I.

' Referring to the drawings, a is a base templates or measurements is facilitated. a a

plate providedwith a bracket 6 in which is mounted a radius wheel 0. having a grooved and flanged periphery. The back of the said'radius wheel is cut away so as to provide aflat part 0} which takes support 5 against thebracket b; a central removable through pin (2 serves to secure, the radius the tube to be bent, the bending roller f carried by the lever will be in correct position to engage the shield. The grooved elongated shield g is formed with thin edges and is adapted to fit within the flanges of the radius wheel whereby the grooved inner face of the shield embraces a suitable length of that portion of the tube It to bebent which lies in advance of the bending point, and thereby spreads the bending pressure and avoids the tube being damaged, during the operation, 2' is a stud adapted to be fitted in one of a number of holes in the base plate and forming an abutment against which the length of pipe preceding the bending point may bear.

lhis said stud i is formed with one groovedside 2' and one curved and. grooved sided as shown to form an efficient support for the tube as hereinafter set forth.

A machine of a given size and strength is preferably provided with a series of interchangeable radius wheels, tube shields, and bearing studs, and a series of holes in the lever (see Fig. 5) for, adjusting the position of the roller so as to allow of'the machine being used for tubes of different diameters within its range.

In operatiomthe tube It is passed into the machine so as to bear against the stud i and with the portion to be bent lying against the grooved periphery of the radius wheel 0, the elongated grooved shield g is now slid over the tube between the same and the bending roller f and in suchposition as to lie between the flanges of the radius wheel so that the, tube will be adequately supported around its circumference between the shield. and the former or radius wheel as the bending proceeds.

When the parts are thus assembled with the handle of the cranked lever lying at substantially 90 with the tube the bending roller f will be conveniently brought to correct position in advance of the bending point to engage the shield at the beforementioned point on a radial line approximately beyond the bending point so as to exert the bending force in such advanced position during the bending operation that distortion of the tube both on the internal and external portion of the bend is avoided. I find the best results are obtained when the roller operates within an angle of 10 to 25 beyond the bending point.

As soon as the lever e is pulled forward the roller f travels over the back of the shield g and therethrough transmits the bending pressure to the tube and bends the bent tribe may be removed. If it is inconvenient to draw out the bent tube from the front the pivotal pin (Z can be removed which allows both the operating lever together with the bent tulmto be released.

lln operating upon the end of a'tube the other part of which has already been bent in a reverse curve the stud 2' is so placed that its curved and grooved face 5 receives the bentvpart of the tube. The said stud may be placed in one or other-of the holes as may be necessary by the bend required and the position of the bending roller.

By dispensing with the use of a cover plate for the radius wheels or forms and by using flanged radius Wheels such as 0 supported from the base by a bracket such as 7) together with a knife edged shield such as g and interchangeable stops such as a the position of which may be altered by the series'o-f holes j the bending operation is'suiiiciently exposed to View to enable the operator to bend a tube to a template or desired measurements with great facility.

Further, it will be seen that in the process of bending, the tube is protected by the shield through which" the bending force is transmitted by the roller operating beyond the bending point as described and thus the bending force is applied in suchma-nner as to prevent damage to the tubeand for this reason the use offilling is not required even with tubes of very small gauge.

What I claim as my invention and desire to secure by Letters Patent is 1. A tube bending machine of'the type referred to, comprising the combination of a radius wheel, and a shield with coacting faces grooved and proportioned to the tube to be bent, a lever mounted to turn on the axis of the radius wheel, and a bending Ell] roller mounted on'said lever to contact with the back of the shield and transmit the bending force therethrough at a point lying on a radius of said wheel advanced from ten to twenty-five degrees from the radius of the wheel projecting through the bending point of the pipe. Y

2. A tube bending machine, comprising the combination of a radius wheel, and a shield with coacting faces grooved and proportioned to the tube to be bent, a lever mounted to turn on the axis of the radius wheel, a bending roller mounted onsaid lever in position wherethe periphery of the bending roller will contact with the back of the shield at a point on a radius spaced substantially fifteen degrees in advance of the rad us passing through the bending point said' lever supporting the bending roller initially at a point approximately in advance of the bending point.

4:. A tube bending machine of the kind referred to comprising the combination of a radius wheel with curved periphery and flanges extending outwards beyond said curved periphery, a cranked lever carrying an adjustable bending roller, a base plate, a

bracket fixed to said base plate and overhanging said radius Wheel and the pivotal end of said cranked lever, a pivotal pin passingthrough said bracket, lever, and radius wheel and into said base plate, a solid elongated tube shield having its inner face curved to fit the tube and formed with knifelike upper and lower edges so as to pass within'the flanges of the radius Wheel and embrace the tube to be bent; a stop for engagingand supporting the tube and means for changing the position of the stop on the base plate.

. 5. A tube a tube receiving groove and confining bending machine comprising a. base plate, a former on the base plate having- 40 flanges, a grooved shield adapted to project 1 between said flanges and having knife edges adapted to bear against the inner opposite facesofsaid'fianges and cooperate there with to uniformly support the tube, a lever pivoted concentrically t0 the former and offset forwardly in the'direction of swing ing of the lever from ten to twenty-five degrees from the radius of the bending point of-the tube, and a roller mounted on said forwardly offset lever to en a e said shield.

JOHN HENiti? HAWES. 

